1. Field of the Invention
This invention is directed to a coating composition of an acrylic polymer and a crosslinking agent such as a polyisocyanate or a melamine crosslinking agent and contains a highly fluorinated hydroxyl containing additive that forms a finish that remains relatively dirt free under exterior use conditions and is easily cleaned when soiled, for example by washing with water.
2. Description of the Prior Art
Acrylic polymer containing coating compositions crosslinked with a polyisocyanate are well known as shown in Vasta U.S. Pat. No.3,558,564 issued Jan. 26, 1971 and Krueger U.S. Pat. No. 4,156,678 issued May 29, 1979. Coating compositions of blends of acrylic polymers and acrylic polymer containing fluorocarbon constituents that form antiicing coatings are well known. Clear coats containing acrylic polymers having small amounts of fluorocarbon constituents that are applied over metallic base coats to provide auto finishes that have good weatherability, have high water and oil repellence and stain resistance are shown in Sugimura et al U.S. Pat. No. 4,812,337 issued Mar. 14, 1989.
Fluorinated polyurethanes that are used as soil release agents are shown in Gresham U.S. Pat. No. 3,759,874 issued Sep. 18, 1973. Polyurethanes of fluorinated isocyanates that are used as adhesives are shown in Mitsch et al U.S. Pat. No. 3,972,856 issued Aug. 3, 1976. Protective coatings of fluorinated polyurethanes of fluorinated diols or triols are shown in Re et al U.S. Pat. No. 4,782,130 issued Nov. 1, 1988.
There is a need for a fluoro carbon containing additive that can be added to a conventional coating composition that will form a coating composition that is high in solids, can be applied with conventional equipment and cures to a hard, tough, durable and weatherable finish without baking at elevated temperatures and the finish is soil resistant and is easily cleaned. Preferably the coating composition has a low content of fluorocarbon constituents which reduces the cost of the composition since the fluorocarbon constituent is expensive.